В журнале  Physical Chemistry Chemical Physics,   (IF 3,676) опубликована статья с участием сотрудников Института:  Д.С. Одинцова (мнс, ЛЭАСМ), к.х.н. И.К. Шундриной (с.н.с. ЛЭАСМ), д.х.н. Л.А. Шундрина (зав. ЛЭАСМ)

Spectroelectrochemical study of the reduction of 2-methyl-9H-thioxanthene-9-one and its S,S-dioxide and electronic absorption spectra of their molecular ions

doi: 10.1039/D1CP04464H

Abstract

2-Methyl-9H-thioxanthene-9-one (1) and its S,S-dioxide (2) are the precursors of pendant groups that determine the reduction potentials of electro-active polyimides, which exhibit electrochromic behavior and are used in organic electronics. Electrochemical reduction of 1 and 2 leads to the formation of the corresponding persistent radical anions and dianion (for S,S-dioxide). Using 3D spectroelectrochemistry, all anions have been shown to exhibit strong absorption in the UV-VIS-NIR wavelength region. Electronic absorption spectra of 1 and 2 and their negative ions were interpreted using time-dependent DFT. According to the calculations, the most intense electronic transitions of the dianions 1²⁻ and 2²⁻ in the visible region exhibit hypsochromic shift compared to the intense transitions of the corresponding radical anions and have much higher oscillator strengths, which was confirmed experimentally for 2. An empirical kinetic model was proposed based on the analysis of the total charge passed through the cell during electrolysis and on the established mechanism of electrochemical reduction. This model perfectly described the UV-VIS-NIR optical density time dependences observed on 3D spectroelectrochemical surfaces for both compounds 1 and 2. This made it possible to explain the differences in the electrochromic behaviour of ambibolar electro-active polyimides with pendant groups based on 1, 2.

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В  журнале  The Journal of Physical Chemistry Letters,   (IF 6,475) опубликована статья с участием сотрудницы Института  к.ф.-м.н. И.В. Береговой (снс, ЛЭАСМ)

An Updated View of Primary Ionization Processes in Polar Liquids

doi: 10.1021/acs.jpclett.1c03388

Abstract

According to picosecond radiolysis data, primary radical cations in irradiated carbonates are very rapidly deprotonated. At the same time, analysis of the radiation-induced fluorescence from carbonate solutions indicates the formation of solvent-related radical cationic species with a relatively long lifetime. We use quantum chemical methods to develop a model of carbonate ionization that reconciles these conflicting data. Using ethylene carbonate as an example and assuming that its molecules exist in solution as a collection of dimeric associates, we show that both processes are the result of the loss of an electron from such dimers. This demonstrates that the generally accepted conceptualization of a primary ionization event, based on the idea of the formation of a radical cation of an individual molecule of an irradiated substance, requires revision in the case of polar aprotic liquids that tend to form molecular associates.

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В журнале Pharmaceutics (IF 6,321) опубликована статья с участием сотрудников Института   к.х.н.,  Е. В. Суслов (зам.дир. по науке, завлаб ЛНТПС),  Е.С. Можайцева (мнс ЛНТПС), А.А. Мункуева (аспирант, мнс ЛНТПС), Д. Цыпышева (мнс ЛФАВ, аспирант), к.х.н. А.Д. Рогачева (снс ЛФАВ) и д.х.н. К.П. Волчо (гнс, ЛФАВ):

Novel Multitarget Hydroxamic Acids with a Natural Origin CAP Group against Alzheimer’s Disease: Synthesis, Docking and Biological Evaluation

В журнале International Journal of Molecular Sciences   (IF=5,923) опубликована статья  с участием сотрудника Института: к.х.н.С.С. Хуцишвили (снс ЛМР)

Novel Nanobiocomposites Based on Natural Polysaccharides as Universal Trophic Low-Dose Micronutrients

Spartak S. Khutsishvili,Alla I. Perfileva,Olga A. Nozhkina,Tatjana V. Ganenko and Konstantin V. Krutovsky

Int. J. Mol. Sci. 2021, 22(21), 12006
Publication Date: November 5, 2021

(This article belongs to the Special Issue Biopolymer Composites: Synthesis, properties and Applications)

Abstract

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В журнале International Journal of Molecular Sciences   (IF=5,923) опубликована статья  с участием сотрудников Института: к.х.н.Ю.Ф. Полиенко (снс ЛАС) и  к.х.н. И.А. Кирилюка (завлаб ЛАС)

Peek Inside the Water Mixtures of Ionic Liquids at Molecular Level: Microscopic Properties Probed by EPR Spectroscopy

Mikhail Yu. Ivanov,Yuliya F. Polienko ,Igor A. Kirilyuk ,Sergey A. Prikhod’ko ,Nicolay Yu. Adonin  and Matvey V. Fedin

Int. J. Mol. Sci. 2021, 22(21), 11900
Publication Date: November 2, 2021

(This article belongs to the Special Issue Advanced Research in Green Chemistry)

Abstract

Many ionic liquids (ILs) can be mixed with water, forming either true solutions or emulsions. This favors their applications in many respects, but at the same time might strongly alter their physicochemical properties. A number of methods exist for studying the macroscopic properties of such mixtures, whereas understanding their characteristics at micro/nanoscale is rather challenging. In this work we investigate microscopic properties, such as viscosity and local structuring, in binary water mixtures of IL [Bmim]BF₄ in liquid and glassy states. For this sake, we use continuous wave and pulse electron paramagnetic resonance (EPR) spectroscopy with dedicated spin probes, located preferably in IL-rich domains or distributed in IL- and water-rich domains. We demonstrate that the glassy-state nanostructuring of IL-rich domains is very similar to that in neat ILs. At the same time, in liquid state the residual water makes local viscosity in IL-rich domains noticeably different compared to neat ILs, even though the overwhelming amount of water is contained in water-rich domains. These results have to be taken into account in various applications of IL-water mixtures, especially in those cases demanding the combinations of optimum micro- and macroscopic characteristics. View Full-Text

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В журнале Journal of Chemical Physics   (IF=3,488) опубликована статья  с участием сотрудников Института: к.х.н. С.А. Добрынина (нс, ЛАС), к.х.н. Д.А. Морозова (снс, ЛАС), к.х.н.Ю.Ф. Полиенко (снс ЛАС), Ю.В. Хорошуновой (мнс, ЛОЭ) и  к.х.н. И.А. Кирилюка (завлаб ЛАС)

The effects of nitroxide structure upon 1H Overhauser dynamic nuclear polarization efficacy at ultralow-field

Paul Fehling, Kai Buckenmaier, Sergey A. Dobrynin, Denis A. Morozov, Yuliya F. Polienko, Yulia V. Khoroshunova, Yulia Borozdina, Philipp Mayer, Jörn Engelmann, Klaus Scheffler, Goran Angelovski, and Igor A. Kirilyuk

J. Chem. Phys. 155, 144203 (2021)
Publication Date: Oct. 14, 2021

Abstract

The efficacy in ¹H Overhauser dynamic nuclear polarization in liquids at ultralow magnetic field (ULF, B₀ = 92 ± 0.8 µT) and polarization field (B_p = 1–10 mT) was studied for a broad variety of 26 different spin probes. Among others, piperidine, pyrrolidine, and pyrroline radicals specifically synthesized for this study, along with some well-established commercially available nitroxides, were investigated. Isotope-substituted variants, some sterically shielded reduction-resistant nitroxides, and some biradicals were included in the measurements. The maximal achievable enhancement, E_max, and the radio frequency power, P_1/2, needed for reaching E_max/2 were measured. Physico-chemical features such as molecular weight, spectral linewidth, heterocyclic structure, different types of substituents, deuteration, and ¹⁵N-labeling as well as the difference between monoradicals and biradicals were investigated. For the unmodified nitroxide radicals, the E_max values correlate with the molecular weight. The P_1/2 values correlate with the spectral linewidth and are additionally influenced by the type of substituents neighboring the nitroxide group. The nitroxide biradicals with high intramolecular spin–spin coupling show low performance. Nitroxides enriched with ¹⁵N and/or ²H afford significantly higher |E_max| and require lower power to do so, compared to their unmodified counterparts containing at natural abundance predominantly ¹⁴N and ¹H. The results allow for a correlation of chemical features with physical hyperpolarization-related properties and indicate that small nitroxides with narrow spectral lines have clear advantages for the use in Overhauser dynamic nuclear polarization experiments. Perdeuteration and ¹⁵N-labeling can be used to additionally boost the spin probe performance.

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В журнале International Journal of Molecular Sciences   (IF=5,923) опубликована статья  с участием сотрудников Института: А.С. Филимонова (мнс ЛНТПС),  д.х.н. О.И. Лузиной (внс ЛФАВ), чл.-корр. РАН, проф. д.х.н. Н.Ф. Салахутдинова (зав.отделом ЛФАВ)

New Hybrid Compounds Combining Fragments of Usnic Acid and Thioether Are Inhibitors of Human Enzymes TDP1, TDP2 and PARP1

Nadezhda S. Dyrkheeva, Aleksandr S. Filimonov, Olga A. Luzina, Kristina A. Orlova,Irina A. Chernyshova,Tatyana E. Kornienko, Anastasia A. Malakhova, Sergey P. Medvedev, Alexandra L. Zakharenko, Ekaterina S. Ilina, Rashid O. Anarbaev, Konstantin N. Naumenko, Kristina V. Klabenkova, Ekaterina A. Burakova, Dmitry A. Stetsenko, Suren M. Zakian,
Nariman F. Salakhutdinov and Olga I. Lavrik

Int. J. Mol. Sci. 2021, 22(21), 11336
Publication Date:October 20, 2021

(This article belongs to the Special Issue Inhibition of DNA Repair Enzymes as a Valuable Pharmaceutical Approach)

Abstract

Tyrosyl-DNA phosphodiesterase 1 (TDP1) catalyzes the cleavage of the phosphodiester bond between the tyrosine residue of topoisomerase 1 (TOP1) and the 3′ phosphate of DNA in the single-strand break generated by TOP1. TDP1 promotes the cleavage of the stable DNA–TOP1 complexes with the TOP1 inhibitor topotecan, which is a clinically used anticancer drug. This article reports the synthesis and study of usnic acid thioether and sulfoxide derivatives that efficiently suppress TDP1 activity, with IC₅₀ values in the 1.4–25.2 μM range. The structure of the heterocyclic substituent introduced into the dibenzofuran core affects the TDP1 inhibitory efficiency of the compounds. A five-membered heterocyclic fragment was shown to be most pharmacophoric among the others. Sulfoxide derivatives were less cytotoxic than their thioester analogs. We observed an uncompetitive type of inhibition for the four most effective inhibitors of TDP1. The anticancer effect of TOP1 inhibitors can be enhanced by the simultaneous inhibition of PARP1, TDP1, and TDP2. Some of the compounds inhibited not only TDP1 but also TDP2 and/or PARP1, but at significantly higher concentration ranges than TDP1. Leader compound 10a showed promising synergy on HeLa cells in conjunction with the TOP1 inhibitor topotecan.

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В журнале The Journal of the American Chemical Society (JACS) (IF 15,419) опубликована статья с участием д.ф.-м.н., профессора    Елены Григорьевны Багрянской (Директор института):

Benchmark Test and Guidelines for DEER/PELDOR Experiments on Nitroxide-Labeled Biomolecules

J. Am. Chem. Soc. 2021, 143, 43, 17875-17890 Publication Date:October 19, 2021

https://doi.org/10.1021/jacs.1c07371

ABSTRACT

Distance distribution information obtained by pulsed dipolar EPR spectroscopy provides an important contribution to many studies in structural biology. Increasingly, such information is used in integrative structural modeling, where it delivers unique restraints on the width of conformational ensembles. In order to ensure reliability of the structural models and of biological conclusions, we herein define quality standards for sample preparation and characterization, for measurements of distributed dipole–dipole couplings between paramagnetic labels, for conversion of the primary time-domain data into distance distributions, for interpreting these distributions, and for reporting results. These guidelines are substantiated by a multi-laboratory benchmark study and by analysis of data sets with known distance distribution ground truth. The study and the guidelines focus on proteins labeled with nitroxides and on double electron–electron resonance (DEER aka PELDOR) measurements and provide suggestions on how to proceed analogously in other cases.

 

Abstract

Thermally resistant air-stable organic triradicals with a quartet ground state and a large energy gap between spin states are still unique compounds. In this work, we succeeded to design and prepare the first highly stable triradical, consisting of oxoverdazyl and nitronyl nitroxide radical fragments, with a quartet ground state. The triradical and its diradical precursor were synthesized via a palladium-catalyzed cross-coupling reaction of diiodoverdazyl with nitronyl nitroxide-2-ide gold(I) complex. Both paramagnetic compounds were fully characterized by single-crystal X-ray diffraction analysis, superconducting quantum interference device magnetometry, EPR spectroscopy in various matrices, and cyclic voltammetry. In the diradical, the verdazyl and nitronyl nitroxide centers demonstrated full reversibility of redox process, while for the triradical, the electrochemical reduction and oxidation proceed at practically the same redox potentials, but become quasi-reversible. A series of high-level CASSCF/NEVPT2 calculations was performed to predict inter- and intramolecular exchange interactions in crystals of di- and triradicals and to establish their magnetic motifs. Based on the predicted magnetic motifs, the temperature dependences of the magnetic susceptibility were analyzed, and the singlet–triplet (135 ± 10 cm^–1) and doublet-quartet (17 ± 2 and 152 ± 19 cm^–1) splitting was found to be moderate. Unique high stability of synthesized verdazyl-nitronylnitroxide triradical opens new perspectives for further functionalization and design of high-spin systems with four or more spins.

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Benchmark Test and Guidelines for DEER/PELDOR Experiments on Nitroxide-Labeled Biomolecules   

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An Efficient Access to 3,5-Disubstituted Isoxazoles with Anthranilate Ester Moiety: Alkaloid Lappaconitine – Aryl Conjugates with an Isoxazole Linker

Dr. Kirill P. Cheremnykh, Dr. Victor A. Savelyev, Prof. Elvira E. Shults

Asian Journal of Organic Chemistry, 2021, V. 10, N 10, Pp. 2638-2643

На сайте журнала Applied Organometallic Chemistry   (IF=4,015) опубликована статья  с участием сотрудников Института д.х.н. И.И. Олейника (в.н.с, ЛЭАСМ) и  к.х.н. И.В. Олейник (с.н.с, ЛЭАСМ) 

α,α'-Bis (imino)-2,3:5,6-bis (pentamethylene)pyridines appended with benzhydryl and cycloalkyl substituents: Probing their effectiveness as tunable N,N,N-supports for cobalt ethylene polymerization catalysts

Mingyang Han, Ivan I. Oleynik, Yanping Ma, Irina V. Oleynik, Gregory A. Solan, Tongling Liang, Wen-Hua Sun

Applied Organometallic Chemistry,  
Online Version of Record before inclusion in an issue, e6429

Abstract

A single-pot method has been utilized to prepare the bis(cycloheptyl)fused N,N,N-cobalt (II) chloride complexes, [2,3:5,6-{C₄H₈C(NAr)}₂C₅H₃N]CoCl₂ (Ar = 2,6-(C₅H₉)₂–4-(CHPh₂)C₆H₂ Co1, 2-(C₅H₉)-4,6-(CHPh₂)₂C₆H₂ Co2, 2-(C₆H₁₁)-4,6-(CHPh₂)₂C₆H₂ Co3, 2-(C₈H₁₅)-4,6-(CHPh₂)₂C₆H₂ Co4, 2-(C₁₂H₂₃)-4,6-(CHPh₂)₂C₆H₂ Co5) in reasonable yields. The molecular structure of Co1 highlights not only the steric shielding of the metal center provided by the N-2,6-dicyclopentyl-4-benzhydrylphenyl groups but also the trans-configuration of the puckered sections of the two fused seven-membered rings. Besides this structural characterization, all complexes have been characterized by elemental analysis and Fourier transform infrared spectroscopy (FT-IR) spectroscopy. In the presence of modified methylaluminoxane (MMAO) or methylaluminoxane (MAO), Co1–Co5 afforded highly linear polyethylenes (T_m′s > 126°C) with dispersities that were influenced by the type of aluminoxane activator [M_w/M_n range: 1.53–1.81 (MMAO) vs. 8.96–15.5 (MAO)]. In common to both co-catalysts, the catalytic activity of the precatalysts fell in the order: Co1 > Co2 > Co5 > Co4 ~ Co3, reflecting the differences in steric/electronic properties of the ortho-cycloalkyl substituents. In terms of thermostability of the catalyst, Co1/MMAO attained optimal performance at 30°C (2.04 × 10⁶ g PE mol⁻¹[Co] h⁻¹), while Co1/MAO reached it at 60°C albeit with lower productivity (0.70 × 10⁶ g PE mol⁻¹[Co] h⁻¹). In general, the polyethylenes were of reasonably high molecular weight (e.g., between 39.9 and 65.8 kg mol⁻¹ using MMAO) which can be linked to the steric hindrance imposed on chain transfer by the cycloalkyl and benzhydryl ortho-substituents.

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На сайте журнала Advanced Functional Materials    (IF 18,808) опубликована статья с участием сотрудников Института  И.П. Коскина  (мнс, ЛОЭ), к.х.н.К.С. Мельниковой-Беккер (снс, ЛОЭ), к.х.н. А.А. Сониной (нс, ЛОЭ), А.Д. Куимова (мнс, ЛОЭ), к.х.н. И.К. Шундриной (снс, ЛАСМ)  и к.х.н. М.С. Казанцева (завлаб ЛОЭ)

Selectively Fluorinated Furan-Phenylene Co-Oligomers Pave the Way to Bright Ambipolar Light-Emitting Electronic Devices

Abstract

Linearly conjugated oligomers attract ever-growing attention as promising systems for organic optoelectronics because of their inherent lucky combination of high charge mobility and bright luminescence. Among them, furan-phenylene co-oligomers (FPCOs) are distinguished by outstanding solubility, very bright luminescence, and good hole-transport properties; however, furan-containing organic semiconductors generally lack electron transport, which makes it impossible to utilize them in efficient light-emitting electronic devices, specifically, ambipolar light-emitting transistors. In this work, 1,4-bis(5-phenylfuran-2-yl)benzene (FP5) derivatives are synthesized with the fully/partially fluorinated central and edge phenyl rings. It is shown that the selective fluorination of FPCOs lowers the energies of frontier molecular orbitals, maintaining the bandgap, solubility, and bright luminescence, dramatically improves the photostability, tunes the π-π stacked packing, and allows the first realization of electron transport in FPCOs. It is found that selectively fluorinated 2,2′-(2,3,5,6-tetrafluoro-1,4-phenylene)bis[5-(3,5-difluorophenyl)furan] demonstrates well-balanced ambipolar charge transport and efficient electroluminescence in an organic light-emitting transistor (OLET) with external quantum and luminous efficiencies as high as 0.63% and 5 cdA⁻¹, respectively, which are among the best reported for OLETs. The findings show that “smart” fluorination is a powerful tool to fine-tune the stability and performance of linearly conjugated small molecules for organic optoelectronics.

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В журнале Computational and Structural Biotechnology Journal (IF 7,271) опубликована статья  с участием директора Института   д.ф.-м..н. проф. Е.Г. Багрянской :

Two alternative conformations of mRNA in the human ribosome during elongation and termination of translation as revealed by EPR spectroscopy

Abstract

The conformation of mRNA in the region of the human 80S ribosome decoding site was monitored using 11-mer mRNA analogues that bore nitroxide spin labels attached to the terminal nucleotide bases. Intramolecular spin–spin distances were measured by DEER/PELDOR spectroscopy in model complexes mimicking different states of the 80S ribosome during elongation and termination of translation. The measurements revealed that in all studied complexes, mRNA exists in two alternative conformations, whose ratios are different in post-translocation, pre-translocation and termination complexes. We found that the presence of a tRNA molecule at the ribosomal A site decreases the relative share of the more extended mRNA conformation, whereas the binding of eRF1 (alone or in a complex with eRF3) results in the opposite effect. In the termination complexes, the ratios of mRNA conformations are practically the same, indicating that a part of mRNA bound in the ribosome channel does not undergo significant structural alterations in the course of completion of the translation. Our results contribute to the understanding of mRNA molecular dynamics in the mammalian ribosome channel during translation.

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